Incubator hoods on incubators or generally on thermotherapy apparatus for premature or newborn babies are usually equipped with flaps, which make it possible to open the incubator hood and to have access to the premature or newborn baby from the outside. The problem that may occur with such flaps is that the flap is not closed properly but only creates the impression that it is closed. A comparable example is a door that does not shut and therefore unexpectedly opens later on. The risk of an improperly closed incubator hood is that the climate in the interior of the incubator or the thermotherapy apparatus is compromised.